[c-nsp] Speed limitations - RF problem or IP ?

[Miguel]

 Hello,

Does anyone know what the best things to do when you have speed problems
with cable modems in different downstream/upstream?

This is the scenario:

uBR 10K with about 17000 customers. Each downstream is configured with
256qam and all upstream have 16qam of modulation.
In some cases the upstreams have a load-balance configuration with 2 or 3
upstream per optical node.

There are no problems of SNR and FEC. All values are regular... And the used
bandwidth are low..

After that, in some upstream can not go to the 20Mb of download Bandwidth
and with the configuration used, should arrive without problem to 37Mb...

I tested several cable modems and the problem still remain ...

Someone has suggestions or ways of action to overcome this type of problem?

Thks for your help